CoDelBlockingQueue (Javadocs [I2P+ 2.13.0+]

java.lang.Object
- java.util.AbstractCollection<E>
- - java.util.AbstractQueue<E>
  - - java.util.concurrent.LinkedBlockingQueue<E>
    - - net.i2p.router.util.CoDelBlockingQueue<E>

Type Parameters:
E - type of elements in this queue
All Implemented Interfaces:
Serializable, Iterable<E>, Collection<E>, BlockingQueue<E>, Queue<E>
```
public class CoDelBlockingQueue<E extends CDQEntry>
extends LinkedBlockingQueue<E>
```
CoDel (Controlled Delay) implementation of Active Queue Management.
Implements the CoDel algorithm from RFC 8289 for managing queue congestion and controlling latency through packet dropping. Provides active queue management with automatic dropping when queue delay exceeds configurable thresholds.
Code and comments are derived from RFC 8289 appendix, implementing the standard CoDel algorithm with configurable target delay and interval parameters. Monitors queue sojourn time and drops packets when above target to maintain optimal throughput and latency characteristics.
Input methods are overridden to add timestamps for delay calculation. Output methods implement AQM behavior with comprehensive statistics tracking for performance monitoring.
See Also:
Serialized Form

Field Summary
Fields
Modifier and Type Field and Description
static String PROP_CODEL_INTERVAL
PROP_CODEL_INTERVAL.
static String PROP_CODEL_TARGET
PROP_CODEL_TARGET.

Fields
Modifier and Type	Field and Description
`static String`	`PROP_CODEL_INTERVAL` PROP_CODEL_INTERVAL.
`static String`	`PROP_CODEL_TARGET` PROP_CODEL_TARGET.

Constructor Summary

Constructors
Constructor and Description
`CoDelBlockingQueue(I2PAppContext ctx, String name, int capacity)` Constructs a queue with default CoDel target and interval from properties.
`CoDelBlockingQueue(I2PAppContext ctx, String name, int capacity, int target, int interval)` Constructs a queue with explicit CoDel target and interval.

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`boolean`	`add(E o)` add.
`void`	`clear()` clear.
`void`	`dispose()` Remove this instance from the tuning list.
`int`	`drainAllTo(Collection<? super E> c)` Drains all, without updating stats or dropping.
`int`	`drainTo(Collection<? super E> c)` Updates stats and possibly drops while draining.
`int`	`drainTo(Collection<? super E> c, int maxElements)` Updates stats and possibly drops while draining.
`static void`	`expungeStaleInstances()` Remove cleared (GC'd) weak references from the list.
`long`	`getInterval()` Returns the current CoDel interval in ms.
`long`	`getTarget()` Returns the current CoDel target delay in ms.
`boolean`	`isBacklogged()` Has the head of the queue been waiting too long, or is the queue almost full?
`boolean`	`offer(E o)` offer.
`boolean`	`offer(E o, long timeout, TimeUnit unit)` offer.
`E`	`poll()` poll.
`void`	`put(E o)` put.
`void`	`setInterval(long interval)` Sets the current CoDel interval in ms.
`void`	`setTarget(long target)` Sets the current CoDel target delay in ms.
`E`	`take()` take.
`static void`	`updateAllIntervals(long interval)` Update interval on all active CoDelBlockingQueue instances.
`static void`	`updateAllTargets(long target)` Update target on all active CoDelBlockingQueue instances.

Methods inherited from class java.util.concurrent.LinkedBlockingQueue
contains, iterator, peek, poll, remainingCapacity, remove, size, spliterator, toArray, toArray, toString

Methods inherited from class java.util.AbstractQueue
addAll, element, remove

Methods inherited from class java.util.AbstractCollection
containsAll, isEmpty, removeAll, retainAll

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.util.Queue
element, remove

Methods inherited from interface java.util.Collection
addAll, containsAll, equals, hashCode, isEmpty, parallelStream, removeAll, removeIf, retainAll, stream

Methods inherited from interface java.lang.Iterable
forEach

- Field Detail
  - PROP_CODEL_INTERVAL
```
public static final String PROP_CODEL_INTERVAL
```
    PROP_CODEL_INTERVAL.
    See Also:
    Constant Field Values
  - PROP_CODEL_TARGET
```
public static final String PROP_CODEL_TARGET
```
    PROP_CODEL_TARGET.
    See Also:
    Constant Field Values
- Constructor Detail
  - CoDelBlockingQueue
```
public CoDelBlockingQueue(I2PAppContext ctx,
                          String name,
                          int capacity)
```
    Constructs a queue with default CoDel target and interval from properties.
    Parameters:
    ctx - the I2P application context
    name - name for this queue instance
    capacity - the maximum capacity of the queue
  - CoDelBlockingQueue
```
public CoDelBlockingQueue(I2PAppContext ctx,
                          String name,
                          int capacity,
                          int target,
                          int interval)
```
    Constructs a queue with explicit CoDel target and interval.
    Parameters:
    ctx - the I2P application context
    name - for stats
    capacity - the maximum capacity of the queue
    target - the target
    interval - how long above target to start dropping (ms)
- Method Detail
  - add
```
public boolean add(E o)
```
    add.
    Specified by:
    add in interface Collection<E extends CDQEntry>
    Specified by:
    add in interface BlockingQueue<E extends CDQEntry>
    Specified by:
    add in interface Queue<E extends CDQEntry>
    Overrides:
    add in class AbstractQueue<E extends CDQEntry>
  - clear
```
public void clear()
```
    clear.
    Specified by:
    clear in interface Collection<E extends CDQEntry>
    Overrides:
    clear in class LinkedBlockingQueue<E extends CDQEntry>
  - dispose
```
public void dispose()
```
    Remove this instance from the tuning list. Called when the owning tunnel/queue is no longer active.
  - drainAllTo
```
public int drainAllTo(Collection<? super E> c)
```
    Drains all, without updating stats or dropping.
    Parameters:
    c - the collection to drain into
    Returns:
    the number of elements drained
  - drainTo
```
public int drainTo(Collection<? super E> c)
```
    Updates stats and possibly drops while draining. May exit early if a CoDel drop occurs (poll() returns null for a dropped item).
    Specified by:
    drainTo in interface BlockingQueue<E extends CDQEntry>
    Overrides:
    drainTo in class LinkedBlockingQueue<E extends CDQEntry>
  - drainTo
```
public int drainTo(Collection<? super E> c,
                   int maxElements)
```
    Updates stats and possibly drops while draining. May exit early if a CoDel drop occurs (poll() returns null for a dropped item).
    Specified by:
    drainTo in interface BlockingQueue<E extends CDQEntry>
    Overrides:
    drainTo in class LinkedBlockingQueue<E extends CDQEntry>
  - expungeStaleInstances
```
public static void expungeStaleInstances()
```
    Remove cleared (GC'd) weak references from the list.
  - getInterval
```
public long getInterval()
```
    Returns the current CoDel interval in ms.
    Returns:
    the interval in ms
  - getTarget
```
public long getTarget()
```
    Returns the current CoDel target delay in ms.
    Returns:
    the target delay in ms
  - isBacklogged
```
public boolean isBacklogged()
```
    Has the head of the queue been waiting too long, or is the queue almost full?
    Returns:
    true if the queue is backlogged
  - offer
```
public boolean offer(E o)
```
    offer.
    Specified by:
    offer in interface BlockingQueue<E extends CDQEntry>
    Specified by:
    offer in interface Queue<E extends CDQEntry>
    Overrides:
    offer in class LinkedBlockingQueue<E extends CDQEntry>
  - offer
```
public boolean offer(E o,
                     long timeout,
                     TimeUnit unit)
              throws InterruptedException
```
    offer.
    Specified by:
    offer in interface BlockingQueue<E extends CDQEntry>
    Overrides:
    offer in class LinkedBlockingQueue<E extends CDQEntry>
    Throws:
    InterruptedException
  - poll
```
public E poll()
```
    poll.
    Specified by:
    poll in interface Queue<E extends CDQEntry>
    Overrides:
    poll in class LinkedBlockingQueue<E extends CDQEntry>
  - put
```
public void put(E o)
         throws InterruptedException
```
    put.
    Specified by:
    put in interface BlockingQueue<E extends CDQEntry>
    Overrides:
    put in class LinkedBlockingQueue<E extends CDQEntry>
    Throws:
    InterruptedException
  - setInterval
```
public void setInterval(long interval)
```
    Sets the current CoDel interval in ms.
    Parameters:
    interval - the new interval in ms
  - setTarget
```
public void setTarget(long target)
```
    Sets the current CoDel target delay in ms.
    Parameters:
    target - the new target delay in ms
  - take
```
public E take()
       throws InterruptedException
```
    take.
    Specified by:
    take in interface BlockingQueue<E extends CDQEntry>
    Overrides:
    take in class LinkedBlockingQueue<E extends CDQEntry>
    Throws:
    InterruptedException
  - updateAllIntervals
```
public static void updateAllIntervals(long interval)
```
    Update interval on all active CoDelBlockingQueue instances.
    Parameters:
    interval - the new interval in ms
  - updateAllTargets
```
public static void updateAllTargets(long target)
```
    Update target on all active CoDelBlockingQueue instances.
    Parameters:
    target - the new target delay in ms

Class CoDelBlockingQueue<E extends CDQEntry>

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.util.concurrent.LinkedBlockingQueue

Methods inherited from class java.util.AbstractQueue

Methods inherited from class java.util.AbstractCollection

Methods inherited from class java.lang.Object

Methods inherited from interface java.util.Queue

Methods inherited from interface java.util.Collection

Methods inherited from interface java.lang.Iterable

Field Detail

PROP_CODEL_INTERVAL

PROP_CODEL_TARGET

Constructor Detail

CoDelBlockingQueue

CoDelBlockingQueue

Method Detail

add

clear

dispose

drainAllTo

drainTo

drainTo

expungeStaleInstances

getInterval

getTarget

isBacklogged

offer

offer

poll

put

setInterval

setTarget

take

updateAllIntervals

updateAllTargets